Engraving cutter selection help

[john dakinParticipant @johndakin59277]

I have a CNC router that I want to use for engraving on 3mm thick brass plates and need some advice on choosing the right cutter, I use 3.175mm shank cutters and i need to engrave 3mm high letters onto half hard brass sheet, not the leaded type brass, I dont need to go very deep, i was thinking of 30 or 60 degree cutters, i dont understand about the tip size, i have seen .002 tip cutters on ebay, any help or advice on this please,

[john dakinParticipant @johndakin59277]

[Nick HulmeParticipant @nickhulme30114]

The tip size is the angled flat ground at the tip which determines the size of the smallest feature you can cut, the smaller the tip the more delicate the cutter will be in use.

– Nick

[John HaineParticipant @johnhaine32865]

I made these from 3mm plate for an engine builder – described elsewhere on this forum. Engraving used a 1mm slot drill (carbide). I carved out a lot of brass to give 1.5mm deep relief letters.

If you use an ordinary engraving cutter, it's best for inlayed letters, or ones done in outline. I think that the cutter form is basically conical at 30 or 60 degrees but with the point truncated so the flat tip diameter is (in your example) .002 (units? Inches I would guess.). So that's the thinnest line you can cut, then the additional thickness is set by the depth of cut and the cone angle – a bit of trigonometry would give that.

If you don't have engraving software I can recommend F-Engrave – it's free and versatile, does multi-line, and can V-carve an image (as used for the example above in fact).

[Author]

Posts